The present invention relates to a feminine hygienic pad which is convenient for use.
There is the general tendency that a feminine hygienic pad is replaced with a new pad at the time of using a toilet even when the sheet of a fluid-absorbing material still has the absorbing ability, and the used pad is disposed.
Development of feminine hygienic pads has mainly been focused on increasing the ability to absorb fluid. However, further increase in this ability is rather meaningless when the above tendency is taken into consideration.
In order to replace a feminine hygienic pad every time using a toilet, several pads must be brought along as replacements when traveling outside the home. Several pads are rather bulky although recent pads are made compact, and this situation causes inconvenience.
Therefore, when women are dressed in a fashionable manner to carry several pads necessitates the carrying of a handbag large enough to carry several pads.
Young women such as student girls who feel shyness to a large extent tend to dislike using a toilet for a long time. However, taking feminine hygienic pads with them to school or on a trip causes inconvenience with respect to the place for keeping the pads and the place and time for replacing the pads in a limited time and space.
Accordingly, the present invention has an object of providing a multi-layer feminine hygienic pad which does not require bringing many pads along as replacements, reduces the troublesome handling to attach the pad to a desired place of an underwear to once with a plurality of composite absorption sheets, and can reduce the time necessary for replacing a used composite absorption sheet with a fresh sheet to a great extent. The present invention also has the object of providing a process for producing the above multi-layer feminine hygienic pad.
The invention takes into account the following: sheets for absorption of fluid can be made very thin and have a great absorbing ability because of the progress in the fluid-absorbing materials made of water-absorbing macromolecular compounds; even when 2 to 5 sheets of the fluid-absorbing material are laminated together in conventional feminine hygienic pads which are disposed after a single use of a package, the thickness of the laminate is not much increased and the feeling during the use and the appearance do not change much because the sheet of a fluid-absorbing material is very thin before it absorbs fluid; and when 2 to 5 conventional sheets of a fluid-absorbing material are laminated together in the condition that they are separated from each other, an entirely fresh feminine hygienic layer can be exposed by simply peeling off the sheet of a fluid-absorbing material at the upper layer after use, and the same condition as that of a new feminine hygienic pad can be brought about in a short time. The result can be that the effect corresponding to attaching 2 to 5 packages of a conventional feminine hygienic pad can be realized by attaching a single package of the feminine hygienic pad and the necessity of bringing along replacement packages of feminine hygienic pads is eliminated. To attain the inventive objects a multi-layer feminine hygienic pad is provided which comprises a laminate sheet containing sheets of a fluid-absorbing material, enables easy removal of the used upper sheet of the fluid-absorbing material, and can conveniently be produced. A process for producing this multi-layer feminine hygienic pad is also provided.
Sheets of fluid-absorption having a multi-layer structure are known for increasing the absorbed amount or to prevent leaking at the sides of the pads. However, a structure which prevents permeation of a fluid absorbed at an upper layer into a sheet fluid-absorbing material laminated at lower layers is not known. In other words, the laminate structure in which individual layers of fluid-absorption are separated with separating layers which do not allow invasion of fluid, and which enables peeling off a layer from another layer easily by fingers although the individual layers are firmly fixed to their own positions, has not been known.
Accordingly, the present invention provides:
(1) A multi-layer feminine hygienic pad comprising: a laminate of two or more composite absorption sheets in which an upper composite absorption sheet comprising a sheet of a fluid-absorbing material and an upper backing sheet laminated to the lower side of the sheet of a fluid-absorbing material is laid on top of a lower composite absorption sheet comprising a sheet of a fluid-absorbing material and a lower backing sheet which has a dimension larger than the dimension of the sheet of a fluid-absorbing material and is laminated to the lower side of the sheet of a fluid-absorbing material, and peripheral part of the lower backing sheet outside the area of the sheet of a fluid-absorbing material of the lower composite absorption sheet and peripheral part of the upper backing sheet of the upper composite absorption sheet are temporarily attached together at least at two opposite edges of the peripheral parts; and a release film coated with a pressure-sensitive adhesive and attached to the lower side of a backing sheet of a lowest composite absorption sheet;
(2) A multi-layer feminine hygienic pad described in (1) wherein the peripheral part of the lower backing sheet of the lower composite absorption sheet and the peripheral part of the upper backing sheet of the upper composite absorption sheet are temporarily attached together with a layer of a pressure-sensitive adhesive disposed between the peripheral parts by pressing the peripheral parts to each other;
(3) A multi-layer feminine hygienic pad described in (2) wherein the layer of a pressure-sensitive adhesive is disposed on the lower side of upper composite absorption sheet;
(4) A multi-layer feminine hygienic pad described in (2) wherein a layer of a releasing agent is disposed between the layer of a pressure-sensitive adhesive and the peripheral part of the lower backing sheet of the lower composite absorption sheet;
(5) A multi-layer feminine hygienic pad described in (1) wherein the lower backing sheet and the upper backing sheet are each made of a thermoplastic resin, and the peripheral part of the lower backing sheet of the lower composite absorption sheet and the peripheral part of the upper backing sheet of the upper composite absorption sheet are temporarily attached together by intermediate melt adhesion using an agent for preventing melt adhesion disposed between the peripheral parts;
(6) A multi-layer feminine hygienic pad described in (5) wherein the intermediate melt adhesion is made by melt cutting using a heated blade;
(7) A multi-layer feminine hygienic pad described in (1) wherein whole or a portion of the peripheral part of the lower backing sheet of the lower composite absorption sheet and whole or a portion of the peripheral part of the upper backing sheet of the upper composite absorption sheet are temporarily attached together with a layer of a heat-sensitive adhesive disposed between the peripheral parts by heat pressing the peripherals parts to each other;
(8) A multi-layer feminine hygienic pad described in (1) wherein the upper backing sheet of the upper composite absorption sheet and the lower backing sheet of the lower composite absorption sheet forming the laminate of two or more composite absorption sheets are made of a single continuous sheet which is folded at the boundary line of the upper backing sheet and the lower backing sheet and has two perforation lines in the vicinity of the boundary line;
(9) A multi-layer feminine hygienic pad described in (8) wherein the upper side of the lower composite absorption sheet and the lower side of the upper composite absorption sheet are temporarily attached together with an adhesive material along edges of the lower absorption sheet and the upper composite absorption sheet opposite to the folded boundary line;
(10) A multi-layer feminine hygienic pad described in (1) wherein the backing sheets of the composite absorption sheets are temporarily attached together in a manner that the backing sheets of the composite absorption sheets which are all laid on top of another are completely attached to each other by heat sealing at least at two opposite edges of the peripheral parts of the backing sheets, and perforation lines are formed at inner parts along all heat sealed parts so that the completely attached backing sheets can be separated from each other at the perforation lines;
(11) A multi-layer feminine hygienic pad described in (1) wherein the peripheral part of the lower backing sheet of the lower composite absorption sheet and the peripheral part of the upper backing sheet of the upper composite absorption sheet are temporarily attached together at least at two opposite edges of the peripheral parts by pressing the edges to each other by a large mechanical pressure;
(12) A multi-layer feminine hygienic pad described in (11) wherein the peripheral part of the lower backing sheet and the peripheral part of the upper backing sheet have protrusions and depressions formed by pressing the peripheral parts by a press and are temporarily attached together by fitting the protrusions and the depressions of the lower backing sheet to the depressions and the protrusions of the upper backing sheet, respectively;
(13) A multi-layer feminine hygienic pad comprising: a laminate of two or more composite absorption sheets in which the composite absorption sheet comprises a sheet of a fluid-absorbing material and a backing sheet having approximately the same dimension as the dimension of the fluid-absorbing material, and whole or a portion of the lower side of an upper backing sheet of an upper composite absorption sheet is temporarily attached to the upper side of a lower composite absorption sheet; and a release film coated with a pressure-sensitive adhesive and attached to the lower side of a backing sheet of the lowest composite absorption sheet;
(14) A multi-layer feminine hygienic pad described in (13) wherein whole or a portion of the lower side of the upper composite absorption sheet is coated with a heat-sensitive adhesive or a pressure-sensitive adhesive having a small adhesive strength, and the composite absorption sheets are temporarily attached together with a layer of the adhesive;
(15) A multi-layer feminine hygienic pad comprising a laminate of two or more composite absorption sheets in which the composite absorption sheet comprises a sheet of a fluid-absorbing material and a backing sheet laminated to the lower side of the fluid absorbing material, each backing sheet has a peripheral part which is extended from periphery of a backing sheet of another composite absorption sheet disposed directly below, a combined extended peripheral part is formed by the successively extended peripheral parts of the backing sheets, the lower side of the combined extended peripheral part of the backing sheets and the lower side of a backing sheet of a lowest composite absorption sheet are each coated with a layer of a pressure-sensitive adhesive, and whole layers of a pressure-sensitive adhesive are covered with a single sheet of a release film to form a laminate integrally fixed by the single sheet of a release film;
(16) A composite absorption sheet for a multi-layer feminine hygienic pad comprising a composite absorption sheet and a film which is laminated to the lower side of the composite absorption sheet, has an opening, and contains the composite absorption sheet by turning inside out;
(17) A process for producing a multi-layer feminine hygienic pad which continuously produces the multi-layer feminine hygienic pad by using two or more long sheets of a thermoplastic resin for backing sheet, two or more long sheets of a porous film of a thermoplastic resin, and two or more sheets of a fluid-absorbing macromolecular compound as materials and comprises continuously laying the long sheet of a thermoplastic resin for backing sheet on the upper side of the long sheet of a porous film of a thermoplastic resin, pressing side edge parts of the two long sheets which have been laid together and an adhesive disposed between the side edge parts of the long sheets to each other to prepare a temporarily attached laminate sheet, laying a plurality of the temporarily attached laminate sheets thus prepared on top of another with the sheets of a fluid-absorbing macromolecular compound disposed between the laminate sheets, and heat sealing or melt cutting side edges of the laminate sheets to form an intermediate melt adhesion between the long sheets in the same laminate sheet and to heat seal a long sheet of a thermoplastic resin for backing sheet in one laminate sheet to a long sheet of a porous film of a thermoplastic resin in another laminate sheet disposed directly below and a long sheet of a porous film of a thermoplastic resin in one laminate sheet to a long sheet of a thermoplastic for backing sheet in another laminate sheet disposed directly above;
(18) A process for producing a multi-layer feminine hygienic pad which continuously produces the multi-layer feminine hygienic pad by using two or more long sheets of a thermoplastic resin for backing sheet, two or more long sheets of a porous film of a thermoplastic resin, and two or more long sheets of a fluid-absorbing macromolecular compound as materials and comprises continuously laying the long sheet of a thermoplastic resin for backing sheet on the upper side of the long sheet of a porous film of a thermoplastic resin, pressing side edge parts of the two long sheets which have been laid together and an adhesive disposed between the side edge parts of the long sheets to each other to prepare a temporarily attached laminate sheet, laying a plurality of the temporarily attached laminate sheets thus prepared and a plurality of the long sheets of a fluid-absorbing material having a narrower width than the width of the temporarily attached laminate sheet alternately on top of another to prepare an alternating laminate sheet, laminating one long sheet of a porous film of a thermoplastic resin for an upper surface to the upper side of the uppermost layer of the alternating laminate sheet and one long backing sheet of a thermoplastic resin for a lower surface to the lower side of the lowest layer of the alternating laminate to prepare a long multi-layer laminate sheet containing a prescribed number of the sheet of a fluid-absorbing macromolecular compound, heat sealing or melt cutting side edges of the long multi-layer laminate sheets to heat seal a long sheet of a thermoplastic resin for backing sheet in one laminate sheet to a long sheet of a porous film of a thermoplastic resin in another laminate sheet disposed directly below or to the long backing sheet of a thermoplastic resin for a lower surface disposed directly below and a long sheet of a porous film of a thermoplastic resin in one laminate sheet to a long sheet of a thermoplastic resin for backing sheet in another laminate sheet disposed directly above or to the long sheet of a porous film of a thermoplastic resin for an upper surface disposed directly above and to form an intermediate melt adhesion between the long sheets in the same laminate sheet by the heat sealing or melt cutting in the presence of an adhesive, and cutting the thus prepared long multi-layer laminate to a prescribed length;
(19) A process described in (18) wherein the sheet of a fluid-absorbing macromolecular compound is a fabric;
(20) A process for producing a multi-layer feminine hygienic pad comprising preparing a temporarily attached laminate sheet by continuously laying a long sheet of a porous film of a thermoplastic resin on the upper side of a long sheet of a thermoplastic resin for backing sheets and then by pressing the two long sheets together with an adhesive disposed between the two long sheets, coating another long sheet of a thermoplastic resin for backing sheet with a pressure-sensitive adhesive on the lower side and attaching a release film made of a thermoplastic resin on the coated side of the sheet, disposing sheets of a fluid-absorbing macromolecular compound having a width smaller than the width of the temporarily attached laminate sheet and a prescribed length on the long sheet of a thermoplastic resin for backing sheet attached with a release film at positions separated by a prescribed distance in a manner that the longitudinal direction of the sheets of a fluid-absorbing macromolecular compound is parallel with or perpendicular to the longitudinal direction of the long sheet, laying the temporarily attached laminate sheet on the long sheet of a thermoplastic resin for backing sheet on which the sheets of a fluid-absorbing macromolecular compound have been disposed, disposing sheets of a fluid-absorbing macromolecular compound having the same size as that described above at positions separated by the prescribed distance in a manner that the sheets of a fluid-absorbing macromolecular compound are placed over the corresponding sheets on the long sheet disposed below, optionally repeating the steps of laminating the temporarily attached laminate sheet and disposing the absorbing sheets of a macromolecular compound having the same size as that described above one or more times, laminating a long sheet of a porous film of a thermoplastic resin on the uppermost layer to prepare a long composite laminate sheet having a prescribed number of the sheet of a fluid-absorbing macromolecular compound, continuously feeding the thus prepared long composite laminate sheet to a table of a heat sealing process, attaching the temporarily attached laminate sheets in the long composite laminate sheet to each other by heat sealing or melt cutting at edges outside the sheets of a fluid-absorbing macromolecular compound, and finally melt cutting or pressing under heating followed by mechanically cutting the thus worked long composite laminate sheet at positions between the sheets of a fluid-absorbing macromolecular compound disposed inside the long composite laminate sheet to separate the long composite laminate sheet into pieces each containing one sheet of a fluid-absorbing macromolecular compound; and
(21) A process for producing a multi-layer feminine hygienic pad comprising preparing a temporarily attached laminate sheet by continuously laying a long sheet of a porous film of a thermoplastic resin on the upper side of a long sheet of a thermoplastic resin for backing sheet and then by pressing the two long sheets together with an adhesive disposed between the two long sheets, disposing sheets of a fluid-absorbing macromolecular compound having a width smaller than the width of the temporarily attached laminate sheet and a prescribed length on another long sheet of a thermoplastic resin for backing sheet at positions separated by a prescribed distance in a manner that the longitudinal direction of the sheets of a fluid-absorbing macromolecular compound is parallel with or perpendicular to the longitudinal direction of the long sheet, laying the temporarily attached laminate sheet on the long sheet of backing sheet on which the sheets of a fluid-absorbing macromolecular compound have been disposed, disposing sheets of a fluid-absorbing macromolecular compound having the same size as that described above at positions separated by a prescribed distance in a manner that the sheets of a fluid-absorbing macromolecular compound are placed over the corresponding sheets on the long sheet disposed below, optionally repeating the steps of laminating the temporarily attached laminate sheet and disposing the absorbing sheets of a macromolecular compound having the same size as that described above one or more times, laminating a long sheet of a porous film of a thermoplastic resin on the uppermost layer to prepare a long composite laminate sheet having a prescribed number of the sheet of a fluid-absorbing macromolecular compound, continuously feeding the thus prepared long composite laminate sheet to a table of a heat sealing process, attaching the temporarily attached laminate sheets in the long composite laminate sheet to each other by heat sealing or melt cutting at edges outside the sheets of a fluid-absorbing macromolecular compound, attaching a long sheet of a release film of a thermoplastic resin coated with a pressure-sensitive adhesive at the central part of the lower side of the prepared long composite laminate sheet before or after the step of heat sealing, and finally melt cutting or pressing under heating followed by mechanically cutting the thus worked long composite laminate sheet at positions between the sheets of a fluid-absorbing macromolecular compound disposed inside the long composite laminate sheet to separate the long composite laminate sheet into pieces each containing one sheet of a fluid-absorbing macromolecular compound.